Childhood origins of heart disease

It’s a well-known phenomenon that many acquired diseases in adults have their origins in childhood.

Common problems like high blood pressure and obesity begin to occur through bad habits or possibly through illnesses these children have suffered. The RCH Cardiology team believes that these other childhood conditions have an effect on the health of blood vessels and the heart. Thanks to the support of RCH1000, they are investigating this theory.

Diseases characterised by inflammation like obesity, inflammatory bowel disease and arthritis are known to increase the incidence of heart attacks and strokes. However, it’s yet to be determined whether the diseases or their treatment cause the acceleration of cardiovascular problems.

There are a number of ways to detect early abnormal changes in the structure and function of blood vessels which cause heart disease. If these changes are proven to be present in young people with chronic illness, it would allow for earlier identification of at-risk individuals and potentially earlier treatment or preventative measures.

Several research studies play an important part in this project.

Barwon Infant Study

Recruiting more than 1,000 children, this study has assessed them from pregnancy to the age of four. Exploring the determinants of early heart disease in Australian children, it uses ultrasound imaging to measure the thickness of large blood vessel walls. So far, the study has shown that faster weight gain in early infancy due to an excessive intake of calories is associated with thicker blood vessel walls, an indicator of increased risk for future cardiac issues.

Longitudinal Study of Australian Children

This study also explores the causes of early heart disease and has been assessing over 1,500 children across Australia since birth. Recently the study made detailed health and lifestyle measurements of these children, including detailed vascular and lung function measurements. Now that data collection is complete, researchers will begin analysing the results, hopefully revealing statistics on factors affecting the early development of the cardiovascular system.

Non-Invasive Measure of Blood Pressure Study

Although the blood pressure cuff provides an important measure of vascular health, it doesn’t measure central aortic pressure, or pressure in the part of the aorta closest to the pumping chamber of the heart. Certain non-invasive devices can determine central aortic blood pressure from a measurement using a standard blood pressure cuff. This is done through a conversion factor, which has been validated in adults, but not children. Researchers are working to derive an age appropriate conversion factor using information from these devices and comparing it to gold-standard invasively derived pressure data.

Studying the Effects of HIV on the Heart

In a collaboration with colleagues in Jakarta, RCH Cardiology have embarked on studies to determine the effects of HIV and the associated drug therapy on children with the virus. Early findings show that HIV seems to alter electrical conduction within heart muscle, as well as heart muscle function, making the heart more prone to abnormal heart rhythms and reduced function.

Pluripotent Stem Cells

The use of stem cells to heal and potentially replace damaged tissues could possibly solve many cardiac issues. A new process called pluripotency, which derives stem cells from mature tissue and simulates them to develop into another cell type, is promising. This has lead the research team to grow heart muscle and vascular cells from patients with pulmonary hypertension. A condition in which the pressure in the blood vessels supplying the lungs is increased to abnormally high levels, pulmonary hypertension places significant strain on the heart. The potential to modify the abnormal vascular cells or use them to study the benefits of new drugs could aid in the development of new treatments.

The outcomes of these studies are being presented at conferences and published in peer reviewed manuscripts. The data generated is also being used for grant submissions to the National Health Medical Research Council to further research.